西南山区大型危岩体灾害地震稳定性数值模拟分析

Stability analysis of largeperilous rock in southwest mountains under earthquake action by numerical simulation

危岩体灾害在我国西南山区分布广泛,开展地震作用下危岩体的稳定性研究是进行灾害风险评价和工程治理措施的前提,具有重要的意义。本文以重庆市武隆县庆口危岩为研究对象,在对危岩体地质环境和变形破坏特征野外详细调查的基础上,运用GeoStuido数值模拟软件,分析了危岩体在自然工况和不同地震动(小震、中震和大震)作用下危岩体的稳定性变化。结果表明:在自然工况下,庆口危岩处于欠稳定状态,在地震工况下,随着输入地震动峰值加速度的增大,危岩体稳定性逐渐降低。在小震作用下,庆口危岩降低至不稳定状态;在中震和大震作用,危岩体稳定性则会明显下降,安全系数最大降低幅度可达33%,危岩体可能会产生剧烈滑动。

Perilous rocks distribute widely in mountainous area in southwestern China.It is of important significance for risk assessment and prevention to analyze the stability of perilous rocks under the earthquake action.Taking the Qingkou perilous rock in Wulong County Chongqing City as the research object,based on detail field investigation into the geological background and the basic characters of the perilous rock the numerical software GeoStudio is used to analyze the stability of the perilous rock under different earthquake actions.Main conclusions are as follows:The Qingkou perilous rock is not stable enough in natural condition,and the stability of perilous rock decreases with the increase of peak acceleration of the ground motion under the earthquake action.Under the action of minor earthquakes,the stability of Qingkou perilous rock reduces to unstable state.Under the moderate and major earthquake,the safety factor gets more lower,the maximum decrease of the safety factor can reach 33%,and the perilous rock has a high possibility to slip violently.